> Suppose two unknown polynomials B and A can be written as> > B/A =N where N is a convergent power series which we know.> > and we also know that> > B/A = k/D where D is another polynomial and k is a constant (k and D are also > known).> > Can we then find B and A??

Have you mis-typed something? Your conditions mean that N = k/D where k and D are already polynomials. You could choose B = k and A = D, or multiply both k and D by any polynomial you liked.